Connection devices of this type which are used particularly for providing a connection within a heat transfer fluid circuit in a motor vehicle are already known. For this purpose, a particular application of such a device is the connection of an inlet or outlet manifold for a heat exchanger, in which the heat exchange fluid must exchange heat with another medium, and a conduit bringing the fluid into or out of this heat exchanger.
The term “manifold” means here generally any fluid transfer means which comprises at least one tubular part such as for example a tube, conduit, a connecting piece, a distance tube, etc.
The function of the connection device is to axially force the neck and protrusion towards one another in order to ensure a seal, preferably by clamping an annular seal between them in a fluidtight manner.
There is already known, in particular through FR 2 738 894, a connection device of this type which is produced in the form of an open collar, generally in the form of a C, and which is assembled in a radial movement, that is to say perpendicular to the common axis of the manifolds.
In these known solutions, the choice of the material making up the collar is essential for providing a mechanical connection. It is a case of a metallic collar, generally made from spring steel, the choice of this material being justified by the need for sufficient flexibility to enable the collar to separate on passing over the manifold and to be at the same time sufficiently rigid to guarantee the holding of the manifolds and to prevent excessively easy extraction of the collar after it is fitted.
These known solutions have in particular the drawback of using an expensive material which in addition must undergo high-cost anticorrosion treatment so that the total price of the component is uncompetitive compared with a solution using a plastics material.
In addition, although this collar is held on the manifolds by the spring effect of the material used, it nevertheless remains vulnerable to extraction.
However, for certain fluid connections which entail risk, it is necessary to guarantee the prevention of a disconnection of the collar under a very high force.
Moreover, assembling the collar on the manifolds also poses difficulties. This is because the ends of the metallic collar are defined so as to be in abutment on the periphery of the neck, protrusion or manifolds, and thus so as to be able to move away as soon as a radial assembly pressure is exerted.
In these known solutions, the collar has no axial holding stop which would make it possible to guide it at the start of its assembly movement. The result is therefore a high risk of faulty mounting of the collar on the manifolds and therefore a risk of not providing the required seal function.